Description: (from Applicant's Abstract) This purpose of this study is to examine the effectiveness of Parent Management Training (PMT) in children with Tourette's syndrome and explosive, defiant behavior. Although Tourette's syndrome (TS) is defined by chronic motor and phonic tics, clinically-identified children with TS often have co-morbid obsessive-compulsive symptoms (OCS), Attention Deficit Hyperactivity Disorder (ADHD) and/or disruptive behavior. Parents describe these more complex cases as stubborn, irritable, argumentative, emotionally brittle, easily frustrated and prone to tantrums. Whether these problems are part of TS, secondary to TS or an unrelated co-morbid behavioral profile is unknown. For children with this behavior profile, however, the care-taking demands can be extraordinary. Because the tics of TS are involuntary, parents may question the child's capacity to control this disruptive and explosive behavior. This uncertainty threatens parental competence and may lead to inconsistent and insufficient parental control. The purpose of this PMT program is to improve the explosive and defiant behavior in children with TS by enhancing parental management of the disruptive and explosive behavior. PMT has been successfully applied to children with disruptive behavior problems in ADHD, but has not been applied to children with TS. PMT will be compared to standard treatment provided in the Tic Disorder Clinic. Three to four successive waves of children and their families (10 to 12 per wave) will be recruited and then randomly assigned to the 12-session PMT program developed by Barkley and colleagues or twelve weeks of standard treatment in the clinic. The primary outcome measures will include oppositional Defiant Scale and the Clinician's Global Improvement score assessed at midpoint (&week mark) by a clinician who is blind to treatment assignment. The same clinician The same clinician will evaluate the durability of PMT in this population at six weeks and twelve weeks post-treatment. Children who were randomly assigned to standard treatment will be invited to participate in the PMT program and will also be independently assessed at six and twelve weeks. This design will permit two sets of analysis: short-term efficacy (change from baseline in randomly assigned groups after the 11-session intervention); durability of PMT (evidence of sustained benefit up to 12 weeks post-treatment.